如题new_w = Math.round(old_w / tempdouble);
new_h = Math.round(old_h / tempdouble);//计算新图长宽
BufferedImage tag = new BufferedImage(new_w, new_h, BufferedImage.TYPE_INT_RGB);
tag.getGraphics().drawImage(src, 0, 0, new_w, new_h, null);
FileOutputStream newimage = new FileOutputStream(newurl);